Haa-I Tephra

[ Top ] [ Japanese ]

Haa-I Tephra Sawaguri and Kurokawa, 1986

Abbr.: Haa-I

Tephra
Pliocene

Lithofacies: Hornblende orthopyroxene andesite tephra (more than some dozen units)
Lithofacies (Minor): Silt

Host: Hachikokusan Formation
Thickness (Overall): 7 m
Thickness (A unit): 2 - 25 cm

Hachikokusan Formation
[ Upper ]
--------------
Haa-II
--------------
Silt bed
--------------
Haa-I
--------------
[ Lower ]

Hachikokusan region, Niigata pref.
[ Upper ]
--------------
Hachioji Formation
--------------
Suganuma Formation
--------------
Hachikokusan Formation
--------------
Hododaira Formation
--------------
[ Lower ]

------ Conformity, ~~~~~~ Unconformity, ~~~--- Local unconformity, '''/,, Interfingered, :::::: Fault, /--/-- Thrust, +__+__ Ground surface, ?--?-- Unknown

Distribution: Niigata pref.

Kobayashi et al. (1995) Geology of the Kashiwazaki District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 102p. (in Japanese with English abstract 4p.)
Kobayashi et al. (1989) Geology of the Okanomachi District, Quadrangle Series, Scale 1:50,000, Geological Survey of Japan, 112p. (in Japanese with English abstract 5p.)